tconn

I just got the car back on the road after a 3 month clutch change.
I also installed the Zeitronix WB02 at the same time.

I noticed that spool up is taking longer than it seemed to before the clutch
change. The Zeitronix shows 15psi at 3325 rpm. I used to see 15psi before
2900rpm , and this was with a couple of exhaust leaks which have since been
fixed.

The WB02 showes the car is a little on the rich side , 11.5 11.6 under full throttle and as the rpm's increase going to 10.9 -11.2 .
Will this effect spool up !

note: For spool up test I start in third gear at 2000rpm and go full throttle.

Rogue_Ant

Yes, running rich will slow spool, especially in low boost/rpm.


Rogue

fast951

Hi Tim, I would pressure test the intake system.

tconn

Hi John

I'm seeing 16-17mmhg on my vac gauge at idle while warm but I
went out last night and picked up the parts to make a pressure tester anyway.

I'm going to double check the exhaust also.

I was hoping it would just be that the car is runnning rich.

special tool

You need to check the exhaust.
-Intake leak the size of a pencil will reduce HP 20%
-Exhaust leak the size of a pencil will slow spoolup 400 RPM

You can consider this FACT, not speculation.

tconn

ST thanks for the input.
Advise from both you and John is always regarded as "gospel" in my book.

What do you think of the AFR's ?

special tool

Works for me, man.
My last dyno I didn't even breakinto the 12's. The 951 likes to be little rich I think - not just for safety but power too.

No need to be in the 10's though......

Rogue_Ant

You saying that your last WOT pull you were leaner then 12.9-1...!?! On what fuel?

Rogue

special tool

HAAHAHAHA -what? dude, RICHER than 12......

If you run BIG power on an 8 valve 2.5 in the 13 AFR range, you will melt the widefire at #4 and hydrolock 1,2 and 3 if you don't push the clutch in.....

hypothetically speaking, of course.

fast951

Tim, If the air measured by the MAF is not making it to the combustion chamber (leaking out), then the car will run rich and spoolup will be slower.

Of course, this is not the only reason for running rich and for having slower spoolup, but it'll be the forst to check.

Keep in mind, with the hot outside temps, the turbo will spoolup a bit slower.

Rogue_Ant

LOL, yeah its early I didn't think about being richer then 12-1...


Rogue

tconn

Thanks guy's!

I'll check for leaks before adjusting the AFR.

John , the temps were in the low 60's last night with very low humidity.
Hence my concern.

Maciek

Related question, what is the recommended method for checking for exhaust leaks? I have the intake pressure testor, but what do you do about exhaust? Thanks.

rberry951

If they didn't do anything but replace the clutch I would concentrate my search on the areas they touched, exhaust, wastegate. If you are running the Tial in dual port mode it could be as simple as they pinched one of the lines and caused a leak on the wastegate signal. Leaky exhaust is also a high probability given the work you had done.

Regards,
Russell

tconn

Made up my test setup this afternoon. Sure enough I've located one leak and
still tracking down another under the intake.
First leak was where the signal line to the wastegate bolts to the IC pipe.

The tester consists of a PVC cap that I threaded a 1/4" brass "T" into.
On one side of the "T" I installed a gauge. The other side I installed a shut off valve with a QC nipple so I can connect to the compressor hose. I charged the compressor shut it off and then slowly beed air into the intake with the valve.
Seems to work well.